What Causes Brown Menstrual Bleeding And Sensitive Tooth While Having Mirena Coil?

Hi i have the mirena coil in.last month i had a light period it only lasted a day.today my period was due but its light nd brown.over the last two weeks iv been moody down in myself no energy and my boobs were so last week also last week my teeth were seniative.i took a test on mon and it was negative.i juat dont no wat to do